Prostate cancer is the third most common cause of death from cancer in men of all ages and is the most common cause of death from cancer in men over age of 75. Current treatments for prostate cancer include (1) hormonal therapy, (2) chemotherapy, (3) radiation therapy, and (4) surgery. However, they are only effective for patients during the early stages of the disease. There are also undesired side effects associated with each of these treatment modalities. Moreover, for patients with advanced stages of castration-resistant and metastatic prostate cancers, these treatments are only partially effective.
Supplemental or combination therapies may improve the outcome in advanced patients. For instance, patients subjected to androgen ablation therapy with either chemical castration with a LH-RH agonist or surgical castration have benefited by the combination with an antiandrogen like bicalutamide. Patients who failed these hormonal therapies are often benefited by selective chemotherapy such as docetaxel and denosumab and additional hormonal therapy to deplete residual endogenous androgen synthesis (e.g. a CYP17 inhibitor, abiraterone). Despite the improvement, these additional therapies, in general, are only capable of prolonged survival by a few months.
Prognosis and staging of prostate cancer are typically evaluated using the Gleason grading system. A Gleason score is given to prostate cancer based on its microscopic appearance. Cancers with a higher Gleason score are more aggressive and have a worse prognosis. A Gleason score is determined by a pathologist who visually inspects a biopsy sample and then assigning a score to the observed tumor pattern. However, the Gleason system is entirely reliant upon human visual examination, which is prone to error with significant limitations on early detection.
In view of the above, there is an urgent, unmet need for more effective mechanism-based therapies and noninvasive early-stage diagnostic techniques to differentiate indolent from virulent forms of prostate cancer so that overtreatment of this disease can be avoided.